VIN Check Digit Calculator

How VIN Check Digit Calculator Works?

The VIN Check Digit Calculator works by transliterating the 17 Vehicle Identification Number (VIN) characters to numbers, multiplying them by fixed position weights, and writing the remainder modulo 11 in position 9. A remainder of 10 is written as X.

1. 1Enter the 17-character VIN; the letters I, O, and Q are not allowed.
2. 2Transliterate letters: A–H = 1–8, J–N = 1–5, P = 7, R = 9, S–Z = 2–9; digits keep their value.
3. 3Multiply each value by its position weight: 8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2.
4. 4Total the 17 VIN products and divide by 11.
5. 5Write the remainder in position 9, using X for 10.

VIN Check Digit Calculator Formula

The VIN formula is d₉ = (Σ T(cᵢ) × wᵢ) mod 11, with 10 written as X (49 CFR Part 565).

S = Σ T(cᵢ) × wᵢ,  w = 8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2
d₉ = S mod 11,  10 → X

• T(c) is the transliteration value.
• w₉ = 0, so the check digit itself does not count.

1→1×8
M→4×7
8→8×6
G→7×5
D→4×4
M→4×3
9→9×2
A→1×10
K→2×9
P→7×8
0→0×7
4→4×6
2→2×5
7→7×4
8→8×3
8→8×2
S = 351
351 mod 11 = 10 → X
VIN = 1M8GDM9AXKP042788

VIN Check Digit Calculator Conversion Table

The VIN conversion table maps every allowed letter to its transliteration value and shows sample VINs.

Position weights: 8, 7, 6, 5, 4, 3, 2, 10, 0 (check digit), 9, 8, 7, 6, 5, 4, 3, 2.

What is VIN Check Digit Calculator?

A VIN Check Digit Calculator is a tool that computes or verifies the 9th character of a 17-character Vehicle Identification Number. The check digit is mandatory for vehicles sold in the United States and Canada since model year 1981.

European and Asian manufacturers follow ISO 3779 for the VIN structure, and most fill position 9 with a check digit or a Z. The VIN has 3 parts: the World Manufacturer Identifier (WMI), the Vehicle Descriptor Section (VDS), and the Vehicle Identifier Section (VIS).

What are the uses of VIN Check Digit Calculator?

There are 4 main uses of the VIN Check Digit Calculator, including used-car checks, insurance quotes, and registration forms.

• Used-car checks: Buyers spot altered or mistyped VINs before a purchase.
• Insurance quotes: Insurers reject invalid VINs on quote forms.
• Registration forms: Motor vehicle agencies validate VINs on title applications.
• Parts lookup: Parts catalogues confirm the VIN before decoding the model.